The best malaria treatment currently in use, called ART, is not as effective as it once was. Experts recently confirmed ART-resistant malaria in Southeast Asia.
Now researchers are testing a hybrid drug that killed malaria strains grown in the laboratory as well as malaria parasites from patients in Thailand who were resistant to artemisinin combination therapy (ACT). Also, the drug was very effective against malaria that was resistant to both chloroquine (an older drug) and artemisinin.
Malaria drugs work by acting on the digestive vacuole (DV) of the parasite that causes malaria. Following treatment, the DV can mutate so that the drugs are “pumped out” of the DV, allowing the parasite to continue to reproduce.
The new hybrid therapy, tested by researchers at the National University of Singapore, works by blocking the resistance pump of the parasite while at the same time killing the parasite. This dual acting mechanism includes a killing factor (derived from chloroquine) and a second component that blocks the mutated DV pump (known as a chemoreversal agent).
The drug becomes concentrated inside the DV of the drug-resistant parasite and can then effectively kill the parasite.
This is the first time that a hybrid of chloroquine and a newly discovered chemoreversal factor have been used together in a single novel molecule for this purpose.
A single therapy could have several advantages against drug-resistant malaria. Besides being more convenient to take than two separate drugs, it has less risk of drug interactions, may be better absorbed and distributed in the body, and could result in slower development of new resistant strains of malaria.
The results of the initial tests appear in the journal Antimicrobial Agents and Chemotherapy.
Source: National University of Singapore